This volume is the fruit of the eleventh Leuven Encounters in Systematic Theology (LEST XI) which was organized by Leuven's Faculty of Theology and Religious Studies from 11-14 October, 2017. On the occasion of the five-hundredth anniversary of the Reformation, this conference focused on the ongoing need for the renewal and reform of the Churches, a desideratum encapsulated in the well-known adage, Ecclesia semper reformanda. The quest for such renewal constitutes a challenge for theologians of all confessional traditions. This volume focuses particularly on the themes and topics that were at the forefront of the theological controversies which raged during the transitional period between the Middle Ages and the Early Modern Period, some of which are still unresolved. Part I focuses on the foundations of theology, viz. Scripture, tradition(s), and/or reason. Part II investigates the important theological issues that have their roots in the Reformation Era, including the tensile relationship between sin, grace, free will, justification and sanctification, and the controversies related to the Eucharist, including the notion of sacrifice. Part III examines democratization and leadership structures in the Church. Part IV explores what a historically-informed awareness can contribute to an ecumenically-oriented reflection on the renewal and reform of the Church today.